Methods and systems for providing information to a home system regarding a wireless unit roaming in a visited system

ABSTRACT

Methods and systems to provide a home system with information about a wireless unit roaming in a visited system based on information the wireless unit provides to the visited system. A mobile switching center (MSC-V) of the visited system receives the information from the wireless unit and routes a message to an international gateway. In response, the international gateway creates a new message or alters the original message, and transmits the new or altered message to a mobile switching center (MSC-H) of the home system. In response to receipt of the new or altered message, the MSC-H validates the wireless unit (if valid), creates a response to the new or altered message, and routes the response to the international gateway. The response may include an authorization period for the wireless unit and/or OCOS/TCOS information. In response, the international gateway creates a new response or alters the response, and transmits the new or altered response to the MSC-V. In response to receipt of the new or altered response, the MSC-V registers the wireless unit, provides the wireless unit with communication services in the visited system, or otherwise follows instructions in the new or altered response. If the wireless unit moves to an area served by a second MSC-V, the second MSC-V checks with the international gateway about the wireless unit. If an authorization period is in effect, the international gateway may provide a validation of the wireless unit to the second MSC-V without another message to the home system of the wireless unit.

RELATED APPLICATION

The present application claims priority to and the benefit of the priorfiled copending and commonly owned provisional application entitled“SCP/International Gateway—An SS7 Network Element That Performs SS7Message Routing, Call Delivery and PIN Fraud Protection for CellularUsers Internationally,” filed in the United States Patent and TrademarkOffice on Nov. 5, 1998, assigned application Ser. No. 60/107,224, andincorporated herein by reference.

TECHNICAL FIELD

This invention relates to telecommunications, and in particular, to theprovision of information to a home wireless communications system withrespect to a wireless unit that is roaming in a visited wirelesscommunications system.

BACKGROUND OF THE INVENTION

A distinguishing feature of humans as a species is our ability tocommunicate with each other. Our methods of communication have becomeever more sophisticated and have led to the development of wirelesscommunications. Generally, wireless communications are communicationsthat are transmitted through the use of radio frequency (RF) technology.Wireless communications include communications that are transmittedthrough the use of wireless units such as cellular telephones, mobiletelephones, car phones, personal communication service (PCS) units,pagers, and the like, and also may include appropriately equippedcomputers, computer peripherals, and the like.

A wireless unit is particularly useful to a person on the move. Forexample, a person may use his or her wireless unit while driving a car.The wireless communications service to the person's wireless unit isprovided typically by a service provider that may also be referred toherein as a carrier. Typically, a person who obtains wirelesscommunications service from a service provider is generally referred toherein as a subscriber or a user. A subscriber may make or receivecommunications with his or her wireless unit. The term “communication”is used herein to refer to any call, message, announcement, or otherexchange of data or information, whether analog or digital, that may bereceived on a wireless unit or transmitted from a wireless unit, and/ormay be received or transmitted from a wireless unit that is operating aspart of any other device such as a computer.

When a user initiates a communication on his or her wireless unit, abase station in or serving a predetermined geographic area wherein thesubscriber is located receives the communication. The geographic areathat is served with wireless communications service by the carrier isreferred to herein as the service area of the service provider. Theservice provider typically operates a wireless communications network orsystem to provide wireless communications service to the geographicarea. The wireless communications network or system includes thereferenced base station, and other elements such as mobile switchingcenters (MSCs). The wireless communications network also includeselements that interface with the public switched telephone network(PSTN), and other networks and systems so as to provide forcommunications between and among parties using wireless units or usingwireline units.

Upon receipt of a communication from a wireless unit of a user, the basestation transmits the communication to a mobile switching center (MSC)(sometimes referred to as a mobile-service switching center or mobiletelecommunications switching office (MTSO), or switch). In response tothe receipt of the communication, the MSC further routes thecommunication as appropriate. This routing may take the communication toand through the PSTN, to and through the same wireless communicationssystem, to and through another wireless communications system, orcombinations thereof.

In addition to making a call, a subscriber may receive a communicationon his or her wireless unit from a caller. The caller directs his or hercommunication to the number associated with the subscriber's wirelessunit, which is referred to herein as the mobile number of the wirelessunit. The mobile number may be the mobile identification number (MIN) ofthe wireless unit. The communication is routed through the PSTN, throughother networks, and/or wireless communications systems until thecommunication reaches the MSC serving the subscriber's wireless unit.This MSC may be referred to as the serving MSC or the serving switch.The serving MSC then further routes the communication to the wirelessunit.

As noted, a wireless unit is particularly useful when a subscriber is onthe move such as when the subscriber is driving a car. The subscriber'smobility may take the subscriber out of the service area served by theservice provider from whom the subscriber subscribes. In other words,the subscriber's mobility may take the subscriber out of his or her homeservice area served by his or her home service provider or home carrier.The subscriber may move so as to be located in another service area thatis served by a different service provider with whom the subscriber hasno direct business relationship. The subscriber is said to be “roaming”out of his or her home service area and may be referred to as a“roamer”, or “roaming subscriber” in a visited service area that isserved by a visited system. To provide a roaming subscriber withcommunications service, service providers have agreed to follow certainprocedures in the processing of communications with respect to eachother's subscribers. Generally, a roaming subscriber is validated andmay be authenticated by the visited system, which also may be referredto as the visited service provider. Both of these processes (validationand authentication) are used to prevent fraudulent use of wireless unitsand for other reasons. General descriptions of these processes and otherinformation about wireless communications systems may be found in thebook entitled Cellular and PCS—The Big Picture by Lawrence Harte, SteveProkup and Richard Levine (McGraw-Hill 1997).

Generally, in validation, when a wireless unit initiates a communicationin a service area other than its home service area, the visited systemserving that visited service area attempts to find the wireless unit'sidentification (also referred to as registration information) in thevisitor location register (VLR) of an appropriate MSC in the visitedsystem (MSC-V). If the visited system does not find the identification,then the wireless unit is determined to be not registered with thevisited system. Prior to being provided with communications service inthe visited system, a wireless unit typically needs to be registered inthe visited system.

To register the wireless unit in the visited system, the MSC-V takescertain steps. Using the wireless unit's identification (which generallymay include its mobile number, and electronic serial number (ESN),and/or mobile identification number (MIN), if different from the mobilenumber), the visited system sends a message to the wirelesscommunications system (“home system”) which generally provides wirelesscommunications service to the subscriber. Alternatively, or in addition,the visited system may send a message to a clearing house or otherentity other than the home system. The message from the visited systemrequests validation of the visiting wireless unit. The home systemchecks a home location register (HLR) in an appropriate MSC (MSC-H) ofits system. The clearing house or other entity may check a database,table, or other storage medium of its system. A comparison is made withrespect to the identification regarding the wireless unit to determineif the wireless unit is valid. If the wireless unit is valid, then theHLR of the MSC-H and/or the clearing house or other entity responds tothe serving MSC in the visited system that the validation wassuccessful. The HLR in the home system and/or clearing house or otherentity generally keeps track of the information about the location ofthe subscriber in a visited system for use in the future routing ofcalls, etc.

After the serving MSC in the visited system receives confirmation thatthe visiting wireless unit is valid, the communication initiated by thevisiting wireless unit is processed. The VLR of the serving MSC may thentemporarily store the visiting wireless unit's information to validatethe identity of the wireless unit itself rather than requestingvalidation again for the next call.

Validation generally is the mechanism for providing information to thesubscriber's home system with respect to the subscriber's location in avisited system. With this location information, the home system then mayprocess calls that are received for the roaming subscriber. Inparticular, when a home system receives a call for its subscriber, theMSC in that home system (MSC-H) checks its HLR to determine if thewireless unit is operating in the geographic area of the home system.The MSC-H may find that the wireless unit is not located in thegeographic area of the home system, but rather, is roaming in a visitedsystem. The MSC-H may have location information with respect to thewireless unit. If so, the MSC-H sends a request to the visited MSC(MSC-V) for information that will help the MSC-H in routing the call tothe subscriber.

The above processes of validation and call processing are carried outgenerally with respect to communications that occur within the UnitedStates. However, wireless communications between the United States andforeign countries or wireless communications between foreign countrieshave been problematic. Problems arise because the processes describedabove may not be carried out with respect to communications between theUnited States and a foreign country or between foreign countries becauseof the differences in the wireless systems in the respective countries.A wireless system and its related wireline system in a particularcountry may not be networked with the wireless system and its relatedwireline system in a foreign country. Thus, in some cases, informationregarding a wireless unit's roaming location in a visited system is notreported properly to the home system. The lack of reporting isespecially problematic between countries having differences betweentheir respective wireless systems. Without location informationregarding a wireless unit, the home system is unable to route calls tothe wireless unit.

In addition, the problems associated with the fraudulent use of wirelessunits are prevalent in the United States and abroad. Once a wirelessunit is registered in a visited system, the wireless unit may beespecially vulnerable to being cloned or otherwise fraudulently used.

Accordingly, there is a need for methods and systems that providelocation information regarding a wireless unit that is roaming in avisited system to a home system of the wireless unit. Further, there isa need for methods and systems that provides safeguards so as to preventfraudulent use of wireless units as they roam between and amongcountries or systems.

SUMMARY

The present invention includes methods, systems, and apparatus thatrelate to the provision of information to a home wireless communicationssystem regarding a wireless unit that is roaming in a visited wirelesscommunications system. This information may include an identification ofthe serving mobile switching center (MSC) serving the wireless unit inthe visited system. The serving MSC may be identified by its mobileswitching center identification (MSCID) information being included as aparameter in a message that is provided to the home system.Advantageously, the receipt of this information by a home system allowsthe home system to properly route communications to the wireless unitroaming in the visited system, or for other purposes such as delivery ofservices, repair, record keeping, marketing records, etc.

In addition, the methods, systems, and apparatus of the presentinvention provide safeguards so as to prevent fraudulent use of wirelessunits as they roam between and among countries or systems. Theseanti-fraud features include the limitation that only terminatingservices be provided as communications services to a wireless unitroaming in a visited system, and/or the limitation that communicationsservices be provided to a wireless unit roaming in a visited system onlyfor an authorization period.

Generally stated, a wireless unit that is roaming in a visited systemprovides information to a mobile switching center (MSC-V) of the visitedsystem. In response to receipt of the information, the MSC-V routes amessage to an international gateway. The international gateway creates anew message or alters the original message, and transmits the new oraltered message to a mobile switching center (MSC-H) of the home system.The new or altered message may include an identification of the MSC-V,and in particular, may include an identification of the MSC-V by itsMSCID information in a parameter of the new or altered message.

In response to receipt of the new or altered message, the MSC-H mayvalidate the wireless unit (if valid), create a response to the new oraltered message, and route the response to the international gateway.The response may include information related to anti-fraud features. Forexample, the response may include originating and/or terminating service(OCOS/TCOS) information, and in particular, may include an instructionthat the wireless unit be provided with only terminating service as thecommunications service provided in the visited system. As anotherexample, the response may include an authorization period such that thewireless unit is registered and/or is provided with communicationsservice in the visited system only for the authorization period.

In response to receipt of the response, the international gateway maycreate a new response or alter the response, and transmit the new oraltered response to the MSC-V. In response to receipt of the new oraltered response, the MSC-V may register the wireless unit, and/orprovide the wireless unit with communication services in the visitedsystem, and/or otherwise follows instructions in the new or alteredresponse.

Further, an exemplary embodiment of the present invention advantageouslyeliminates the need for an exchange of message and response with thehome system when the wireless unit moves from a first visited system toa second visited system during an authorization period. For example, thewireless unit may be provided with communications services in a firstvisited system during an authorization period. The wireless unit maymove to a second visited system during the authorization period. Theserving MSC in the second visited system checks with the internationalgateway, which in turn, checks whether the authorization period withrespect to the wireless unit has expired. If it has not expired, thenthe international gateway provides the serving MSC in the second visitedsystem with a validation relating to the wireless unit. The secondvisited system provides the wireless unit with communications servicesat least for the remainder of the authorization. It is an advantage thatthe communications service is continued to the wireless unit in thesecond visited system without the second visited system having to checkwith the home system of the wireless unit.

Advantageously, the use of an international gateway in the exchange ofmessages between the MSC-V of the visited system and the MSC-H of thehome system facilitates the exchange of the messages between theappropriate mobile switching centers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating use of an exemplary internationalgateway in an exemplary environment.

FIG. 2 is a flow diagram illustrating an exemplary method of the presentinvention.

FIG. 3 is a block diagram illustrating an exemplary internationalgateway.

FIG. 4 is a diagram of logical software entities in an exemplaryinternational gateway.

FIG. 5 is a diagram of the message/response exchange handled by anexemplary international gateway with respect to the second registrationof a wireless unit within an authorization period.

DETAILED DESCRIPTION

The present invention includes methods, systems, and apparatus thatrelate to the provision of information to a home wireless communicationssystem regarding a wireless unit that is roaming in a visited wirelesscommunications system. Advantageously, the receipt of this informationby a home system allows the home system to properly route communicationsto the wireless unit roaming in the visited system, or for otherpurposes such as delivery of services, repair, record keeping, marketingrecords, etc. The methods, systems, and apparatus of the presentinvention also include anti-fraud features that may be implemented to atleast minimize if not eliminate instances of unauthorized or fraudulentuse of wireless units.

Generally, the exemplary embodiments of the present inventioncontemplate uses with wireless units such as cellular telephones andpersonal communication service (PCS) units that operate under thestandards of Advanced Mobile Phone Service (AMPS), Call DivisionMultiple Access (CDMA), or Time Division Multiple Access (TDMA).Nonetheless, the principles of the present invention may be applied toother communication devices operating under other standards with theappropriate reconfiguration.

Exemplary embodiments of the present invention include an internationalgateway for use with respect to the referenced wireless communications.Advantageously, the international gateway may be used in a wirelesscommunications system so as to provide a method, system and/or apparatusto provide information regarding a wireless unit that is roaming in theservice area of a visited system. The service area of the visited systemmay be located in the United States or abroad. Further, theinternational gateway may be used in a wireless communications system soas to provide a method, system and/or apparatus of fraud prevention withrespect to the use of wireless units in wireless communications systems.

An exemplary embodiment of the present invention describes theinternational gateway as a stand-alone unit such as may be embodied byor in a service control point (SCP). The reader is cautioned theinternational gateway should not be so limited in embodiment. As well asa stand-alone unit, the international gateway may be incorporated in oras part of another device such as an intelligent peripheral (IP) in awireless communications system, or in other devices. As a result of thefunctions the international gateway carries out, the internationalgateway also may be referred to herein as a personal identification(PIN) validation platform. Moreover, the international gateway may beconsidered to be a series of functions that may be carried out in asingle device or that may be carried out through the use of severaldevices. In the exemplary embodiments described below, generally theinternational gateway functions in accordance with Signaling System 7(SS7) protocols as well as EIA/TIA IS-41 protocols, and thus, may beaccessed through the connectivity between and among network elements ofwireless communications systems and/or wireline communications systemsincluding the public switched telephone network (PSTN). Further, theinternational gateway may be connected to customer service elements ofthe service provider of the international gateway, and even may beaccessed (or partially) accessed by customers of the service provider ofthe international gateway through the Internet or other communicationsnetworks. Generally, customers of the service provider of theinternational gateway include carriers who provide wireless service tosubscribers and who desire to facilitate the provision of wirelessservice to such subscribers when they are roaming, and particularly,roaming in foreign countries or systems.

FIG. 1—An Exemplary International Gateway

FIG. 1 is a block diagram illustrating use of an exemplary internationalgateway 10 in an exemplary environment including a home system 12 and avisited system 14. The home system 12 generally is a wirelesscommunications system provided by a service provider with whom asubscriber has a relationship such that a wireless unit used by thesubscriber typically is registered in a home location register (HLR) 16of a mobile switching center (MSC-H) 18 when the wireless unit islocated in the geographic area served by the MSC-H 18. A communicationfrom a caller and directed to the mobile number of the wireless unit isrouted to the MSC-H 18 for further routing to the called wireless unit.

FIG. 1 also illustrates a visited system 14 including a wireless unit 20that is roaming or visiting in the visited system 14. When the wirelessunit 20 is turned on, typically it provides registration information toa base station 22 serving the cell of the visiting system wherein thewireless unit 20 is roaming. The registration information typicallyincludes the mobile identification number (MIN) for the wireless unit20. The base station 22 generally provides the registration informationto a mobile switching center (MSC-V) 24.

The actions of the exemplary embodiments in response to the receipt bythe MSC-V 24 of the registration information of the wireless unit 20 arefurther explained with reference to the flow diagram of FIG. 2.

FIG. 2—An Exemplary Method

FIG. 2 is a flow diagram illustrating an exemplary method of the presentinvention. Generally, to make and /or receive calls, a wireless unitmust be registered, and if the wireless unit is located in a visitedsystem, then the wireless unit must be registered with that visitedsystem. Exemplary embodiments of the present invention provide for theregistration of a roamer in a visited system particularly when thevisited system is located in a foreign country or uses disparateprocesses from the home system of the roamer.

Assume a subscriber travels from country A to country B and as a roamerdesires to use his or her wireless unit for communications between thetwo countries. Referring to FIG. 2, after start 50, in block 52, theroamer powers-on or turns on his or her wireless unit 20 and generallybegins the registration of the wireless unit 20 with a serving MSC(MSC-V) 24 in a visited system 14 of country B. In block 54, the MSC-V24 receives the registration information that is provided by thewireless unit 20, which information typically includes the ESN and MINof the wireless unit 20. In response to receiving the registrationinformation, the MSC-V 24 generally analyzes the information to theextent the MSC-V 24 determines that the wireless unit 20 is a roamingunit and that the wireless unit 20 is not listed in its visitor'slocation register (VLR) 26. Also, the MSC-V 24 may consult a roameraccess table (RAT) 28. In consulting the RAT, the MSC-V 24 may find anentry 30 in the RAT for the MIN of the wireless unit. The entry 30 mayprovide the MSC-V 24 with an association between the MIN for thewireless unit 20 and a point code for the international gateway 10. Theinformation relating to the association between the wireless unit'sinformation and the point code of the international gateway 10 generallyresults from a relationship established and based on the roamer'ssubscription for wireless service from a service provider that is acustomer or otherwise affiliated with the international gateway 10 orprovider of international gateway services. Thus, the RAT table 28 inthe MSC-V 24 may be set up with the point code of the internationalgateway 10 associated with the visiting subscriber's MIN range in theVLR 26 of the MSC-V 24.

Based on this association between the MIN for the wireless unit 20 andthe point code for the international gateway 10, the MSC-V creates aregistration message, such as a registration notification (REGNOT)message. The MSC-V 24 uses the point code for the international gateway10 as a destination point code in the registration message so as toroute the message to the international gateway 10. The subsystem number(SSN) of the international gateway 10 also may be included in themessage. Typically, the MSC-V 24 sends the message to a routing elementsuch as a service transfer point (STP) in the wireless communicationssystem of country B. The registration message generally contains amobile identification number (MIN), electronic serial number (ESN),system identification (SID), mobile switching center identification(MSCID), destination point code (DPC), originating point code (OPC),primary interexchange carrier (PIC) code, authorization period, and mayinclude other information.

The following table I provides invoke parameters relating to anexemplary registration message such as a registration notificationmessage:

TABLE I MobileIdentificationNumber MIN of the wireless unitMobileSerialNumber ESN of the wireless unit QualificationInformationCode3 = Validation and profile SystemMyTypeCode Vendor of the MSC-V MSCID 3octet ID PC_SSN Octet 1: HLR/VLR Octet 2-4: International Gateway pointcode Octet 3: International Gateway SSN LocationArea MSCID

The international gateway typically is not located in either the homesystem 12 nor the visited system 14. The international gateway 10 isfunctionally connected to the home system 12 and the visited system 14so as to receive and transmit messages, and in particular SS7 messages,between the home system 12 and the visited system 14. In particular, theinternational gateway 10 may be functionally connected to the systems12, 14 such that messages and responses may be routed from a networkelement such as a signal transfer point (STP) (preferably over A links)to the international gateway 10. Additional information relating to anexemplary international gateway is provided below in a discussion ofFIG. 3.

In response to receiving the registration message, in block 56, theinternational gateway 10 generally analyzes the information in themessage to the extent that the international gateway 10 determines thatthe information is to be further routed to a home system 12 of thewireless unit 20. In addition, the international gateway 10 may log orstore the message or pertinent information from the message so that theinternational gateway 10 may appropriately respond to the message at alater time. In addition, the international gateway 10 may maintain thelast known location (i.e., the visited system) of the wireless unit 10by recording and storing the relevant parameters of the registrationmessage.

With respect to the analysis of the information in the message, theinternational gateway 10 may consult a table 32 for information withrespect to the further routing of the message. In consulting the table32, the MSC-V 24 may find an entry 34 in the table 32 for the MIN of thewireless unit 20. The entry 34 may provide the international gateway 10with an association between the MIN for the wireless unit 20 and a pointcode for the MSC-H 18 in the home system 12 of the wireless unit 20.Based on this association between the MIN for the wireless unit 20 andthe point code for MSC-H 18, the international gateway 10 creates a newregistration message. The new message typically is another RegistrationNotification (REGNOT) message. The new registration message includes thepoint code for MSC-H 18 as a destination point code so as to route thenew message to the MSC-H 18. As an alternative to the use of the table32, the information for use of the point code for the MSC-H 18 may beobtained in other manners, such as from other tables, from theinformation in the REGNOT message, or otherwise so that the new messageis routed to the MSC-H 18 of the roamer.

The new registration message does not have to be a “new” message such asa freshly created message. Rather, the registration message receivedfrom the MSC-V 24 may be translated or altered by the internationalgateway 10 to create the new registration message. For example, thedestination point code in the message may be changed from the point codeof the international gateway 10 to the point code of the MSC-H 18.Referring to the invoke parameters listed above in Table I, theinternational gateway 10 preferably changes the PC_SSN field tocorrespond to the MSC-H 18. In addition, the originating point code inthe registration message may be changed from the point code for theMSC-V 24 to the point code for the international gateway 10 in the newregistration message.

Advantageously, the international gateway 10 includes an identificationof the MSC-V 24 in the new registration message. Some clearing houses orother entities that pass information between a visited system and a homesystem fail to include identification of the visited system, andparticularly, of the MSC serving the roaming wireless unit in thevisited system in messages that are passed to the home system. Thisfailure can be understood from the way messages are typicallyconfigured. For example, a clearing house may be sent a registrationmessage from an MSC in a visited system. The originating point code inthis registration message is the point code of the MSC in the visitedsystem. When the clearing house forwards the message to the home system,the clearing house substitutes its own point code for the originatingpoint code in the message. In sum, the identification of the MSC in thevisited system, and even of the visited system, may be lost by thissubstitution of point codes.

The failure of including an identification for the visited system, andin particular, for the MSC in the visited system also may stem from thefact that it may be in the clearing house's interests to withhold suchidentification information from the home system. Without anidentification of the MSC in the visited system, or even of the visitedsystem, the home system has no information as to the location of itsroaming subscriber. The home system cannot independently take actionwith respect to its roaming subscriber. The home system must rely on theclearing house to find the location of its roaming subscriber.

Reliance on the clearing house for information regarding the location ofa roaming wireless unit may be frustrating to the home system forseveral reasons. For example, the clearing house may charge the homesystem for the location information. As another example, the home systemmay be unable to service its roaming subscriber should problems arisewith his/her wireless or with communications service provided to thewireless unit. Without knowing the location of the roaming wirelessunit, the home system is hampered in its efforts to correct any serviceissues. In addition, the home system may be unable to track or otherwisemonitor the traffic, use, and/or other such patterns of its subscribersin the use of their wireless units. Such information may be useful tothe home system in marketing communication services to subscribers andothers.

To overcome the shortcomings with respect to the lack of identificationinformation in the registration information that is passed to the homesystem, the present invention may include a feature whereby theinternational gateway 10 includes an identification of the servingswitch in the visited system in the registration information that isprovided to the home system. In particular, the international gateway 10includes an identification of the MSC-V 24 in the new registrationmessage. This identification is included in the new registration messageas other than a point code for the MSC-V 24. For example, theidentification of the MSC-V may be accomplished by including theswitch's mobile switching center (MSCID) in an appropriate parameter oreven in a parameter designated as MSCID. Advantageously, the home systemis provided with the identification of the switch serving the roamingwireless unit in a visited system and the home system may make use ofthis identification to provide service or to correct servicedeficiencies to the roaming wireless unit. The home system also may makeuse of this identification to carry out traffic, use, and/or otherpattern studies.

After creation of the new registration message, the internationalgateway 10 routes the message to the MSC-H 18 of the wireless unit 20.

Referring still to FIG. 2, in block 58, the MSC-H 18 receives the newregistration message. In response, the MSC-H 18 checks out the newmessage with respect to the wireless unit 20, and may store the newmessage or pertinent information therefrom. Advantageously, the MSC-H 18may log or store the new message or pertinent information therefrom toretain information about the location of the wireless unit 20 so theMSC-H 18 may use the information to route calls to the roamer 20, toresolve service issues, and/or to carry out traffic, use, or otherpattern studies.

In block 60, the MSC-H 18 checks out the new message with respect to thewireless unit 20 by checking whether the wireless unit 20 is valid. Ifthe wireless unit 20 is invalid, then in block 62, the MSC-H 18 createsa response to the new message including a denial of roaming. On theother hand, if the wireless unit 20 is valid, then in block 64, theMSC-H 18 creates a response to the new message including allowance ofroaming. Generally, the response includes the point code of the MSC-H 18as the originating point code and the point code of the internationalgateway 10 as the destination point code. The response generally is aRegistrationNotificationReturn message.

The following table II provides result parameters relating to anexemplary response:

TABLE II SystemMyTypeCode Vendor of the MSC-H AuthorizationDenied Ifset, the international gateway will log this transaction as a frauddetection by the MSC-H AuthorizationPeriod 3 = Validation and profileOriginationIndicator Will be overridden by international gateway DigitsDestination TerminationRestrictionCode Will be overridden byinternational gateway CallingFeaturesIndicator Feature mask DigitsCarrier Id Code

Advantageously, exemplary embodiments of the present invention provideanti-fraud features. Two of these anti-fraud features are initiated inconnection with the response that is created by the MSC-H 18 in responseto the new registration message. With respect to one such anti-fraudfeature, the MSC-H 18 includes originating and/or terminating service(OCOS/TCOS) information in the response. Generally, OCOS/TCOSinformation specifies whether the subscriber or the subscriber's carrierallows for originating and/or terminating service in certain situations.Referring to table II, this information includes theOriginationIndicator and the TerminationRestriction Indicator.(OriginationIndicator=2 prevents the wireless unit from originating acall (OCOS) and TerminationRestrictionCode=1 prevents the wireless unitfrom terminating a call (TCOS)).

Preferably, as an anti-fraud feature, the new response may include aninstruction to the MSC-V 24 to deny originating and/or terminatingservice to the wireless unit 20. The inclusion of this instructionappears to be anti-intuitive in that the purpose of the registrationprocess is to allow the wireless unit 20 eventually to be able toreceive originating and/or terminating service. Advantageously, theinclusion of this instruction is an element of the fraud preventionprovided by exemplary embodiments of the present invention.

For example, the inclusion of the OCOS/TCOS information may instruct theMSC-V 24 to provide the wireless unit 20 with only terminating service.In other words, the wireless unit 20 may receive communications in thevisited system, but may not initiate communications from the visitedsystem. Statistically, most fraudulent uses of a wireless unit 20 areassociated with calls made from a unit, i.e., in originating service,rather than in calls made to a unit. Thus, a limitation on communicationservice to only terminating service to a wireless unit 20 is thought toreduce fraudulent use of the wireless unit 20.

Alternatively, instead of the MSC-H 18 including OCOS/TCOS informationor correct OCOS/TCOS information in the response, the internationalgateway may include the OCOS/TCOS information or override any incorrectOCOS/TCOS information in the response so that the wireless unit will bedenied originating service. The international gateway 10 may add to oroverride the OriginationIndicator and/or the TerminationRestrictionIndicator fields so that the wireless unit is will be provided onlyterminating service.

Another anti-fraud feature that may be initiated in connection with theresponse that is created by the MSC-H 18 in response to the newregistration message relates to an authorization period forcommunication services to be provided to the wireless unit in thevisited system. In particular, the response may include an instructionto the MSC-V 24 with respect to an authorization period. For example, inhigh fraud areas, a wireless unit 20 may be registered with an MSC-V 24only for a limited amount of time (i.e., an authorization period), andthus, the wireless unit 20 may receive communications services only forthat limited amount of time. This limitation may minimize thepossibility the wireless unit 20 may be fraudulently used. In theprevious example, the MSC-V 24 receives the authorization period andkeeps track of the start and stop of the authorization period withrespect to the wireless unit 20. But instead of the MSC-V 24 keepingtrack, the international gateway 10 may keep track of the authorizationperiod with respect to the wireless unit 20. When the authorizationperiod has expired, the international gateway 10 may send an MSInactive(Invoke Last) message to the MSC-V 24.

Referring again to FIG. 2, after either block 62 or 64, in block 66 theMSC-H 18 routes the response to the international gateway 10 by usingthe point code of the MSC-H for the originating point code and by usingthe point code of the international gateway 10 for the destination pointcode.

In block 68, the international gateway 10 receives the response from theMSC-H 18, creates a new response, and routes the new response to theMSC-V 24. In addition, the international gateway 10 may store theresponse or pertinent information from the response. The internationalgateway 10 stores the OCOS/TCOS information that is received in theresponse because such information may be used later, such as in aQualificationDirective message. Generally, the new response includes thepoint code of the international gateway 10 as the originating point codeand the point code (and possibly the system serial number (SSN)) of theMSC-V 24 as the destination point code. If the response includesOCOS/TCOS information, then the international gateway 10 includes theOCOS/TCOS information in the new response. In addition, if the responseincludes an instruction with respect to an authorization period, thenthe international gateway 10 includes the instruction in the newresponse.

The new response does not have to be a “new” response such as a freshlycreated response. Rather, the response may be translated or altered bythe international gateway 10 to create the new response. For example,the destination point code in the message may be changed from the pointcode of the international gateway 10 to the point code of the MSC-V 24.In addition, the new response may be changed from the response receivedfrom the MSC-H 18 in that the originating point code in the response maybe changed from the point code for the MSC-H 18 to the point code forthe international gateway 10.

After creation of the new response, the international gateway 10 routesthe new response to the MSC-V 24. The international gateway 10 may usethe information that the international gateway 10 had stored inconnection with the registration message from the MSC-V 24 so as toappropriately respond to the MSC-V 24. Alternatively, the response fromthe MSC-H 18 may include an identification of the MSC-V 24 such asinclusion of the appropriate MSCID parameter for the MSC-V 24.

Still referring to FIG. 2, in block 70, the MSC-V 24 receives the newresponse, and if appropriate, updates its VLR 26 by registering thewireless unit 20 in its VLR 26 and/or by providing communicationsservice to the wireless unit 20. The MSC-V 24 also may update its VLR 26or other databases with respect to the other information related to thewireless unit 20 such as the OCOS/TCOS information and/or theauthorization period for the registration of the wireless unit and/orthe provision of communication services to the wireless unit 20. TheMSC-V 24 does not view this new response as a “new” response, butrather, as a response to its original registration message. In responseto receiving the new response, the MSC-V 24 may provide the wirelessunit 20 with communication services in the visited system 14.Alternatively, in response to receiving the new response, the MSC-V 24simply may register the wireless unit 20 in its VLR. With respect to theprovision of communication services or the registration of the wirelessunit 20, the MSC-V 24 also may implement an authorization period if theMSC-V 24 has received such instructions. In other words, the MSC-V 24may provide the wireless unit 20 with communication service only for alimited time, or may only maintain the registration of the wireless unit20 in its VLR 26 for a limited time.

If the new response includes OCOS/TCOS information, then the MSC-V 24may provide the wireless unit 20 with communication services in thevisited system 14 based on the OCOS/TCOS information. For example, theOCOS/TCOS information may alert the MSC-V 24 that the wireless unit 20is only to receive terminating service. In other words, the wirelessunit 20 may receive communications, but may not initiate communications.The limitation of communication service to a wireless unit 20 based onOCOS/TCOS information is a fraud control measure and advantage ofexemplary embodiments of the present invention. Statistically, mostfraudulent uses of a wireless unit 20 are associated with calls madefrom a unit, i.e., in originating service, rather than in calls made toa unit. Thus, a limitation on communication service to only terminatingservice to a wireless unit 20 may reduce fraudulent use of the wirelessunit 20. The process ends in block 72.

FIG. 3—An Exemplary International Gateway

FIG. 3 illustrates elements of an exemplary international gateway 10such as may be used in the exchange of messages and responses between avisited system and a home system. The international gateway 10 generallyincludes an interface 73 and a translator 74. The interface 73 functionsas a connection to the communications systems (and elements thereof)which the international gateway serves. An exemplary internationalgateway 10 has an interface 73 that includes SS7 links 75 that receivethe messages and responses, and that pass the messages and responses toan SS7 stack 76. The SS7 stack 76 discriminates and passes the messagesand responses to an IS-41 message handler such as provided by theIntelliSS7-IS41 MAP 77, which is a mapping software. In particular, theSS7 stack 76 passes the data of the IS-41 messages and responses to aparsing library where the message is decoded according to IS-41standards. In the parsing library, the message type, components, andparameters are located in the received messages and responses andstored, (or a pointer stored) in structures which can be then accesseddirectly. Once the messages and responses are parsed, the data then ispassed to the translator 74 carrying out the appropriate operations.

An exemplary international gateway 10 has a translator 74 that includesa state machine based application 78, which controls or manages eachsession. In addition, the translator 74 may include a database accesspart 79 and a database 80 that may contain the table 32 that is used indetermining the routing for a registration message received with respectto a particular wireless unit. More information about the database 80and the information that may be stored in the database 80 or othermemory structure is provided below under the heading “Information WithRespect to the International Gateway”.

Still referring to FIG. 3, the translator 74 may include a messaging andprocess infrastructure 81. This infrastructure 81 provides services suchas message buffering, message passing, timers, task management, etc.

The international gateway 10 also typically includes at least aconnection to an administrative console 82. Information regarding acustomer and/or a user may be provisioned in the international gateway10 through the administrative console 82. A service manager may use theadministrative console 82 to monitor transactions or view transactionsin the transaction log by transaction number or by MIN/ESN. Otherstatistical information relating to the operation of the internationalgateway 10 may be obtained or viewed through the administrative console82.

Further, the international gateway 10 may include an applicationinterface to a network manager that may be accessed and/or operatedthrough the administrative console 82 or through other elements. Forexample, the network manager may be an Openview Network Manageravailable from Hewlett Packard. The application interface may be basedon a simple network management protocol (SNMP) to generate traps andalarms to the network manager. Traps may include unknown message orresponse received and/or PIN modification retries failure.

Generally, the international gateway 10 functions in accordance withSignaling System 7 (SS7) protocols as well as EIA/TIA IS-41 protocols,and thus, may be accessed through the connectivity between and amongnetwork elements of wireless communications systems and/or wirelinecommunications systems. Preferably, the international gateway 10supports the American National Standards Institute (ANSI), InternationalTelecommunications Union (ITU) and ITU International variants of the SS7protocol up to the transaction capabilities application part (TCAP)layer. In particular, the components of the international gateway 10communicate among themselves and other data networks via TCP/IPconnections. The connectivity preferably supports T1/E1 and V .35 atspeeds of up to 64 Kbps. It is further preferred that the internationalgateway 10 generally does not use the Global Title Translation (GTT) inaddressing entities or elements in the systems.

Information With Respect to the International Gateway

The international gateway 10 is set up and continually updated withcurrent information as to users, customers, MSC information, etc. so asto facilitate the exchange of messages and responses between a visitedsystem and a home system of a wireless unit. Generally, theinternational gateway 10 operates pursuant to IS-41 specifications. Forexample, the international gateway 10 starts a timer to time theinterval between routing a new message and receiving a response to thenew message. If appropriate, the international gateway 10 handles atimeout on the response. The international gateway 10 responds witherror messages in the appropriate situations. For example, theinternational gateway 10 responds with a Return Error with an error codeof OperationNotSupported if the international gateway 10 receives amessage for call delivery to a wireless unit that has not registered,that is outside its authorization period, etc. Error codes may includeSystemFailure, ParameterError, UnrecognizedParameterValue;MIN/HLRMismatch, UnrecognizedESN, Operation Sequence Problem, and/orResourceShortage.

The international gateway 10 may include the table 32 and/or database 80as well as other memory or storage facilities with respect to theinformation that is necessary or available with respect to operation ofthe international gateway 10.

User or Subscriber Information

The table 32 or database 80 may include entries or records related tousers. Each entry or record may include the following information or afield (which may be empty until filled) for the following informationwith respect to the user or the wireless unit of the user: a mobileidentification number (MIN); an electronic serial number (ESN); a useror subscriber name; a personal identification number (PIN); a date-timeof last PIN change; a number of retries for PIN change in currentinterval; an MSC-H; a current MSC-V; a previous MSC-V; a date-time oflast successful PIN validation; a number of retries for PIN validationin current interval; a date-time of last Registration Notification; OCOSinformation returned by the MSC-H; TCOS information returned by theMSC-H; a temporary local dialing number (TLDN); user or subscriberstatus; calling features mask; carrier digits; billing identification;destination digits; and/or a date-time of first unsuccessful validationattempts in current interval.

The user or subscriber information may be provisioned in theinternational gateway 10 through the administrative console 82 or inbatch mode through bulk updates transferred from customers.

System Information

The international gateway 10 may store system information with respectto the international gateway 10 in the database 80 or in another storagestructure. For example, the following system configuration informationmay be stored: a system type code; a point code; a subsystem number(SSN); and/or a carrier identification code. Also, the systemconfiguration information may include information relating to the use ofPINs such as the maximum number of retries and the retry interval.Further, the international gateway may store a point code and a SSN foreach of the mobile switching centers (MSCs) or other switches which mayserve as either origination or destination points with respect tomessages and responses that may be sent to and from the internationalgateway 10.

Transaction, Tracing and Audit Information

The international gateway 10 generally carries out transaction andtracing functions with respect to the messages and responses that may besent to and from the international gateway 10. A message and itscorresponding response generally is referred to as a transaction, andthe message and its corresponding response typically includes atransaction number or other identification of the transaction. Theinternational gateway 10 logs the transaction number into a transactionlog (not illustrated), which also may be referred to as log files orinto the database 80. Preferably, the log of the transaction includes atimestamp for the transaction. The international gateway 10 may includea tracing mechanism (not illustrated in FIG. 3) and may include fourlevels of trace messages with each level providing a different amount ofdetailed information. Also, the international gateway 10 may includeaudit trails for all changes made to the database, such as changing aPIN, etc. These audit trails may be recorded and stored.

MSC Information

To facilitate the exchange of messages and responses, the internationalgateway 10 may store information such as attributes with respect tomobile switching centers (MSCs) which are involved in transactionsrelated to a wireless unit. These attributes may include: an MSCidentification; a location; a point code; a subsystem number (SSN); anHLR identification (null if co-located with the MSC); an HLR point code;an HLR SSN; a VLR identification (null if co-located with the MSC); aVLR point code; a VLR subsystem number (SSN); an authentication center(AC) identification; an AC point code; and/or an AC SSN. Thisinformation may be stored in the database 80 or in some other memorystructure. An exemplary embodiment of the international gateway 80stores this information in a functional entity messaging relationshiptable (FEMR table).

Home-Visited Relationship

The international gateway 10 may include a table or other structure thatsets forth a relationship including operating or override values betweenmobile switching centers (MSCs) in a home-visited relationship. Thistable may be used by the international gateway 10 to override valuesthat are present in the user or subscriber entry or record whenappropriate. For example, the visited MSC may be located in a high fraudarea. In that case, an authorization period with respect to theregistration or provision of communications service to a wireless unitmay be instituted through the provision of instructions from the MSC-Hor the international gateway to the MSC-V or otherwise. Thus, this tablemay include the following attributes, information or fields: MSC-Hidentification; MSC-V identification; authorization period; and/orauthorization value.

MSC-NPA Information

The international gateway 10 may have to determine the MSC-H of aparticular wireless unit based on the information that is provided tothe international gateway 10 by the MSC-V. Typically, the internationalgateway 10 uses the MIN of the wireless unit to find the MSC-H (and itspoint code) by using an MSC-NPA information table. Particularly, the MINmay be compared to the entries of NPA-NXX-x blocks that are stored inthe table to determine the NPA-NXX-x block corresponding to the MIN, andthen to determine the MSC-H (and its point code) serving the NPA-NXX-xblock corresponding to the MIN. Thus, an entry in the MSC-NPAinformation table may include the following fields, attributes orinformation: MSC-H identification; and NPA-NXX-x block (being served bythe MSC-H of the entry).

FIG. 4—Logical Software Entities of an Exemplary International Gateway

To facilitate the understanding of the operation of an exemplaryinternational gateway 10, FIG. 4 presents a diagram of logical softwareentities or modules of such a gateway. The modules are presented in thediagram from a logical standpoint. They do not represent separateprocesses that run the international gateway 10, but rather, each modulepresents a functionality that may be used in the gateway.

The modules include INIT 86 which is an initialization function thatbrings up and monitors the application processes on the internationalgateway 10. DB 88 is a database interface in the form of a functionalapplication program interface (API) for interaction with a user. DB 88also includes the database server part that is provided by the vendor ofthe database. TM 90 is a transaction manager which registers with theSS7 processes to gain access to the SS7 stack. The transaction manager90 receives and sends IS-41 messages and responses through the SS7processes. The transaction manager 90 links with the DB 88 in order touse the database server.

Log 92 is a library that provides a functional API to record every IS-41message and response that is sent and received. This API is used torecord all of the IS-41 messages and responses that pass through theinternational gateway 10. Trace 94 is a library that provides debuggingaids for integration and testing. SNMP Agent 96 is a process thatforwards simple network management protocol (SNMP) traps to the networkmanager such as the Openview Network Manager from Hewlett Packard. ThisSNMP Agent 96 also provides a message queue for the other applicationsoftware entities to send event/alarm information, which is converted toa trap and forwarded as appropriate.

Bulk Update 98 is a script that updates the database with large numbersof records or entries, generally with respect to users. Vision Feed 100is a process that provides a continuous feed of all IS-41 messages andresponses being sent and received by the international gateway 10 to aseparate entity for further processing (billing, debugging, networkproblems, etc.). IS-41 API & Vendor's SS7 102 stack is an IS-41 APIbuilt on top of the SS7 stack. The SS7 stack functionality is handledwithin separate processes, i.e., they are not libraries. The IS-41 APIis incorporated in these separate processes. DIR 104 is a platformconfiguration task called the Director. It provides a command lineinterface for configuring the SS7 stack and all network parametersassociated with setting up the international gateway 10 as a functionalnetwork entity. The DIR 104 also can be used to control the SS7 stackprocesses.

FIG. 5—A Second Registration Within an Authorization Period

A wireless unit 20 may be registered with a visited system 14 pursuantto the exemplary method illustrated in FIG. 2. Pursuant to thatexemplary method, the wireless unit 20 may be assigned an authorizationperiod with respect to its registration in the visited system 14 or withrespect to communication services to be provided to the wireless unit inthe visited system 14. Given the mobility of users, the wireless unit 20may be moved from the area served by the MSC-V 24 in the visited system14 to a different area served by another MSC (“new MSC-V” or “secondMSC-V”) in the visited system 14 or in another visited system (“secondvisited system”). The move may occur within the authorization periodinitially assigned to the wireless unit 20. Advantageously, the presentinvention includes embodiments whereby the international gateway 10provides the new MSC-V with a response that indicates the wireless unit20 is valid with respect to registration or the provision of services.The international gateway 10 facilitates this validation by handling theresponse to the new MSC-V rather than exchanging a message and responsewith the MSC-H 18 of the home system 12.

FIG. 5 is a diagram of the message and response exchange between theinternational gateway 10 and the new MSC-V 106 in the visited system 14with respect to the second registration of the wireless unit 20 withinan authorization period. The wireless unit 20 (also referred to as“mobile”) has moved to a different MSC area (i.e., the area served bythe new MSC-V 106).

As illustrated by arrow A, the wireless unit 20 transmits informationsuch as registration information (Mobil Regn) to the new MSC-V 106. Inresponse to receiving the registration information, the new MSC-V 106generally analyzes the information to the extent the new MSC-V 106determines that the wireless unit 20 is a roaming unit and that thewireless unit 20 is not listed in its visitor's location register (VLR).Also, the new MSC-V 106 may consult a roamer access table (RAT). Inconsulting the RAT, the new MSC-V 106 may find an entry in the RAT forthe MIN of the wireless unit. The entry 30 may provide the new MSC-V 106with an association between the MIN for the wireless unit 20 and a pointcode for the international gateway 10. The association between thewireless unit's information and the point code of the internationalgateway 10 generally results from the relationship established and basedon the roamer's subscription for wireless service from a serviceprovider that is a customer or otherwise affiliated with theinternational gateway 10 or provider of international gateway services.Thus, the RAT table in the new MSC-V 106 may be set up with the pointcode of the international gateway 10 associated with the visitingsubscriber's MIN range in the VLR.

Based on this association between the MIN for the wireless unit 20 andthe point code for the international gateway 10, the new MSC-V 106creates a registration notification (REGNOT) message. The new MSC-V 76uses the point code for the international gateway 10 as a destinationpoint code in the registration notification message so as to route themessage to the international gateway 10. The subsystem number (SSN) ofthe international gateway 10 also may be included in the message.Typically, as indicated by arrow B, the new MSC-V 106 sends the REGNOTmessage to a routing element such as a service transfer point (Chile STPas illustrated) 108 in the visited system 14. As indicated by arrow C,the Chile STP 108 routes the REGNOT message to the international gateway10.

In response to receiving the registration notification message, theinternational gateway 10 generally analyzes the information in themessage. In particular, the international gateway 10 may consult itstable 32, database 80, or other storage unit by using the MIN of thewireless unit. In this consultation, the international gateway maydetermine that the wireless unit 20 has registered with the MSC-V 24 andthat the wireless unit's attempt at registration with the new MSC-V 106is a second registration within an authorization period. In addition,the international gateway 10 may log or store the message or pertinentinformation from the message.

Based on the determination that this is a second registration within anauthorization period, the international gateway 10 creates a response tothe registration notification message. The response generally is aRegistrationNotificationReturn (regnot) message.

As indicated by arrow D, the international gateway 10 routes theresponse by way of the appropriate STP (such as illustrated Chile STP108 ), which in turn, as indicated by arrow E, routes the response tothe new MSC-V 106. The response may include OCOS/TCOS information orinstructions with respect to an authorization period. The new MSC-V 106receives the response, and if appropriate, updates its VLR byregistering the wireless unit 20 in its VLR. The new MSC-V 106 also mayupdate its VLR or other databases with respect to the other informationrelated to the wireless unit 20 such as the OCOS/TCOS information or theauthorization period. In response to receiving the response, the newMSC-V 106 may provide the wireless unit 20 with communication servicesin the visited system 14. Alternatively, in response to receiving theresponse, the new MSC-V 106 simply may register the wireless unit 20 inits VLR. With respect to the provision of communication services or theregistration of the wireless unit 20, the new MSC-V also may implementan authorization period if the new MSC-V 106 has received suchinstructions. In other words, the new MSC-V 106 may provide the wirelessunit 20 with communication service only for a limited time, or may onlymaintain the registration of the wireless unit 20 in its VLR for alimited time. Yet another alternative is that the new MSC-V 106 mayreceive OCOS/TCOS information in the response from the internationalgateway 10. If so, then the new MSC-V 106 may provide the wireless unit20 with communications services based on the OCOS/TCOS information. Forexample, assume the response includes OCOS/TCOS information such thatthe new MSC-V 106 is to provide the wireless unit with terminatingservice only as the communication services to be provided to thewireless unit. In that case, the new MSC-V follows through and providesthe wireless unit only with terminating service. If an authorizationperiod also is included in the response, then the new MSC-V may providethe wireless unit with terminating service only and only for theauthorization period.

Still referring to FIG. 5, also as a result of receiving a secondregistration message with respect to the wireless unit 20 within anauthorization period, the international gateway 10 may take action toinform the MSC-V 24 that the wireless unit 20 has left the area servedby the MSC-V 24. In particular, as illustrated in arrow F, theinternational gateway 10 sends a registration cancellation (RegCan)message by way of the appropriate STP (such as the illustrated Chile STP108), which in turn, as indicated by arrow G, routes the registrationcancellation message to the MSC-V 24. In response to receiving theregistration cancellation message, the MSC-V 24 cancels the registrationof the wireless unit 20 from its VLR 26 or as otherwise appropriate. Inaddition, as indicated by arrow H, the MSC-V 24 generally sends aresponse (regcan) to the registration cancellation message by way of theappropriate STP (such as the illustrated Chile STP 108), which in turn,as indicated by arrow I, routes the response to the internationalgateway 10.

Advantageously, the international gateway 10 facilitates the secondregistration of the wireless unit 20 within the authorization period byeliminating any need for a transaction with the MSC-H of the home system12. Also, the international gateway 10 facilitates record keeping in thepreviously visited MSC-V by providing it with instructions to cancel theregistration of the wireless unit 20.

Conclusion

In sum, the exemplary embodiments of the present invention includemethods, systems, and apparatus for providing information to a homesystem regarding a wireless unit roaming in a visited system. Thisinformation is provided with a message that is transmitted from thevisited system where the wireless unit is roaming to an internationalgateway, which in turn, transmits the information to the home system ofthe wireless unit. The information may include an identification of themobile switching center (MSC) serving the wireless unit in the visitedsystem. Advantageously, the information may be used by the home systemto route communications to the wireless unit in the visited system, orfor other purposes such as delivery of services, repair, record keeping,marketing records, etc. The exemplary embodiments also may includeanti-fraud features such as the limitation of communications service tothe wireless unit in the visited system to terminating service only andsuch as the limitation of an authorization period for the provision ofcommunications service to the wireless unit in the visited system.

From the foregoing description of the exemplary embodiments and theseveral alternatives, other alternative constructions of the presentinvention may suggest themselves to those skilled in the art. Therefore,the scope of the present invention is to be limited only to the claimsbelow and the equivalents thereof.

We claim:
 1. A method to allow a wireless unit that is roaming in avisited system to receive communication services in the visited systembased on registration information the wireless unit provides to avisited mobile switching center (MSC-V) in the visited system, themethod comprising: A. in response to receiving the registrationinformation, causing the MSC-V to route a registration message to aninternational gateway; B. in response to receiving the registrationmessage, causing the international gateway i. to create a newregistration message, the new registration message including anidentification of the MSC-V; and ii. to route the new registrationmessage to a home mobile switching center (MSC-H) of the wireless unit;C. in response to receiving the new registration message, causing theMSC-H i. to validate the wireless unit, ii. to create a response, andiii. to route the response to the international gateway; D. in responseto receiving the response, causing the international gateway i. tocreate a new response, and ii. to route the new response to the MSC-V;and E. in response to receiving the new response, causing the MSC-V toprovide the wireless unit with the communication services in the visitedsystem.
 2. The method of claim 1, wherein the identification of theMSC-V comprises a mobile switching center identification (MSCID)parameter.
 3. The method of claim 1, wherein the response comprisesoriginating and/or terminating service (OCOS/TCOS) information; whereinthe new response comprises the OCOS/TCOS information; and wherein theMSC-V is caused to provide the wireless unit with the communicationservices in the visited system based on the OCOS/TCOS information. 4.The method of claim 3, wherein the OCOS/TCOS information comprises aninstruction to provide terminating services only; and wherein the MSC-Vis caused to provide the wireless unit with the terminating servicesonly as the communication services in the visited system based on theOCOS/TCOS information.
 5. The method of claim 1, wherein the MSC-V iscaused to provide the wireless unit with the communication services inthe visited system for an authorization period.
 6. The method of claim5, wherein the MSC-V comprises a first MSC-V, and wherein the wirelessunit moves to an area served by a second MSC-V, further comprising: F.receiving at the second MSC-V second registration information from thewireless unit; G. in response to receiving the second registrationinformation, causing the second MSC-V to reroute a second registrationto the international gateway; H. in response to receiving the secondregistration, causing the international gateway to make a determinationthat the authorization period is in effect; and I. in response to thedetermination, causing the international gateway to send a validationwith respect to the wireless unit to the second MSC-V.
 7. The method ofclaim 6 further comprising: J. in response to receiving the validation,causing the second MSC-V to provide the wireless unit with thecommunication services in the area served by the second MSC-V.
 8. Aninternational gateway for use in obtaining communication services for awireless unit that is roaming in a visited system, the internationalgateway comprising: A. an interface operative to receive a registrationmessage with respect to the wireless unit from an element of the visitedsystem; B. a translator functionally connected to the interface andoperative i. to determine a home system for the wireless unit based onthe registration message, ii. to substitute a point code for an elementof the home system as a destination point code in the registrationmessage, iii. to create a new registration message including anidentification of the element of the visited system, and iv. to causethe new registration message to be routed to the home system; C. theinterface also operative to receive from the home system a response tothe new registration message, the response including originating and/orterminating service (OCOS/TCOS) information with respect to the wirelessunit; and D. the translator also operative i. to substitute a point codefor an element of the visited system as a destination point code in theresponse, and ii. to cause the response to be routed to the element ofthe visited system, whereby the communication services for the wirelessunit are obtained based on the OCOS/TCOS information regarding thewireless unit through an exchange of messages and responses among thevisited system, the international gateway, and the home system.
 9. Theinternational gateway of claim 8, wherein the registration messagecomprises a mobile switching center identification (MSCID) parameter.10. The international gateway of claim 8, wherein the OCOS/TCOSinformation comprises an instruction to provide terminating servicesonly.
 11. The international gateway of claim 8, wherein the visitedsystem comprises a first visited system; wherein the wireless unit movesto an area served by a second visited system; and wherein the interfaceis also operative to receive a second registration message from thesecond visited system; wherein the translator comprises storage, and thetranslator is operative to use the registration message to check thestorage to make a determination that an authorization period assigned tothe wireless unit for provision of the communication services to thewireless unit is in effect; and wherein the translator also is operativeto send a validation of the wireless unit to the second visited system.12. A system to provide a home system with information about a wirelessunit that is roaming in a visited system based on registrationinformation the wireless unit provides to the visited system, the systemcomprising: A. a mobile switching center of the visited system (MSC-V)operative to receive the registration information and in response toroute a registration message to an international gateway; B. theinternational gateway operative to receive the registration message, andin response, to create a new registration message including anidentification of the MSC-V, the identification being other than a pointcode for the MSC-V, and to route the new registration message to a homemobile switching center (MSC-H) in the home system of the wireless unit;and C. the MSC-H operative to receive the new registration message,whereby the home system is provided with the information about thewireless unit including the identification of the MSC-V serving thewireless unit.
 13. The system of claim 12, wherein the MSC-H is furtheroperative in response to receiving the new registration message tovalidate the wireless unit, to create a response including originatingand/or terminating service (OCOS/TCOS) information, and to route theresponse to the international gateway; wherein the international gatewayis further operative to receive the response, to create a new responsebased on the response, the new response including the OCOS/TCOSinformation, and to route the new response to the MSC-V; and the MSC-Vbeing further operative to receive the new response, and to provide thewireless unit with the communication services in the visited systembased on the OCOS/TCOS information.
 14. The system of claim 13 whereinthe OCOS/TCOS information comprises an instruction to provideterminating service only; and wherein the MSC-V is caused to provide thewireless unit with the terminating service only as the communicationservices in the visited system based on the OCOS/TCOS information. 15.The system of claim 13, wherein the MSC-V is further operative toprovide the wireless unit with the communication services in the visitedsystem for an authorization period.
 16. The system of claim 13, whereinthe MSC-V comprises a first MSC-V; wherein the wireless unit moves to anarea served by a second MSC-V; wherein the international gateway isoperative to receive second registration information from the secondMSC-V, to make a determination that an authorization period assigned tothe wireless unit for provision of the communication services to thewireless unit is in effect, and to send a validation to the secondMSC-V; and wherein the second MSC-V in response to receipt of thevalidation provides the wireless unit with the communication services inthe area served by the second MSC-V.
 17. The system of claim 12 whereinthe identification of the MSC-V comprises a mobile switching centeridentification (MSCID) parameter.
 18. In a communications environmentwherein a wireless unit has a registration with a first visited mobileswitching center (MSC), and wherein the wireless unit moves to an areaserved by a second visited MSC, a method for validating the wirelessunit with the second visited MSC without checking with a home system ofthe wireless unit, comprising: A. receiving at the second visited MSCregistration information from the wireless unit; B. in response toreceiving the registration information causing the second visited MSC toroute the registration information to an international gateway; C. inresponse to receiving the registration information, causing theinternational gateway to make a determination that an authorizationperiod assigned to the wireless unit for provision of communicationservices is in effect; and D. in response to the determination, causingthe international gateway to send a validation with respect to thewireless unit to the second visited MSC.
 19. The method of claim 18further comprising: E. upon receiving the validation, causing the secondvisited MSC to consider the wireless unit as validated.
 20. The methodof claim 18 further comprising: E. also in response to thedetermination, causing the international gateway to send a registrationcancellation message to the first visited MSC; and F. in response toreceiving the cancellation message, causing the first visited MSC tocancel the registration of the wireless unit in the first visited MSC.21. The method of claim 18, further comprising: upon receiving thevalidation, causing the second visited MSC to provide the wireless unitwith the communication services.
 22. The method of claim 21 wherein thecommunication services comprise terminating services only.
 23. Themethod of claim 21 wherein the second visited MSC is caused to providethe wireless unit with the communication services for an authorizationperiod.